Air vs Water Cooled Chiller

published on 06/23/2010

A commonly asked question is what chiller is the best, air cooled or water cooled. The answer to that question is that there is no one perfect chiller for all applications. There are many aspects that come into affect when choosing what chiller would be best for a building and its cooling system.

Space is one of these issues. Air cooled chillers can utilize open space, such as a parking lot, roof or ground level area. Water cooled chillers are smaller in size, but require a mechanical room and cooling towers. On the flip side, air cooled chillers can have serious issues with recirculation if there are walls higher than the unit or too many units to close together. If there is a situation where outside walls are required for building code and the unit will not be receiving enough fresh air, then a water cooled application may be the best option.

Sound is another issue than may come into the equation. With any chiller sound is inevitable, air cooled chillers generally have a different decibel because of their fans. There are things that can be done to reduce the sound on chillers, but the best way to negate the sound is to purchase a quieter unit upon decision.

A major part of the equation these days is cost. A detailed cost vs. benefit analysis is advised in any major equipment change. While one chiller may have lower initial costs, it may also have a shorter life span and higher operating costs.

Lifespan is huge in the decision of which unit to choose. Talk to a local contractor, to find out what kind of lifespan they have seen from units similar to those being looked at for the building. There are steps that can be taken to increase lifespan on many units. When speaking with the contractor ask them about these additional steps to ensure the longest life for the unit.

With so many decisions being based on cost and purely cost alone, quality is sometimes thrown out of the equation. Quality is a major factor of the equation and should always be thought of. Quality of the product and the contractor who will be doing the job are both very important.

When it comes time to install a new chiller, these points should help in that field. There are many advantages and disadvantages to both kinds of chillers and some of those are listed below:

Air Cooled Advantages

Install cost is generally lower

Less Maintenance depending on application

No need for a mechanical room

Cooling Tower not needed

Condenser pumps not required

Water Cooled Advantages

Usually have a longer life

Higher efficiency

Indoor placement

Larger tonnage capabilities

Refrigeration containment

Air Cooled Disadvantages

Generally less efficient

Life span is not as long

Usually have more operating noise

Water Cooled Disadvantages

Additional maintenance costs

Water treatment costs

Mechanical room needed

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Alirezaon04/09/2013

what type of chillers (air cooled or water cooled) is suitable for hot climate (60 Celsius environment)?

Charlieon05/29/2012

Hello Robert depending on economics and applications we use 3 different services for coil coatings Advancoat, Belzona,Energyguard.If we can be of any service for your firm in the Florida area please give us a call.

Roberton05/25/2012

Im a chief engineer in Las Vegas and I will be coming to Florida to check on some equipment our company has on our buildings down there what in opinion is the best coating to coat the condenser coils with on an air cooled chiller

Prestonon03/21/2012

Hi Scott. Thank you for your question.
The life of an air cooled chiller is very dependent on it's surrounding climate. Here in South Florida, we have seen machines installed on the coast or near the beach that don't last five years. This is typically due to no coil coating and the coils corroding.
When a machine does have its coils coated properly and is in a relatively low salt area, the machines usually last ten to fifteen years before they need to have their coils replaced.
Keep in mind that the more the coils degrade, the less heat transfer they offer and the more stress the machine has to run under. A higher head pressure is one of the added stresses.

Scott Moranon03/20/2012

I am a building manager at a New Orleans office building. We have a couple of 150 ton 1999 Carrier Flowtronic air cooled chillers. We are wondering what the life expectancy of these machines would be in our harsh climate?

himeshon10/15/2010

still can some body tell me cost analysis for both in detail say for 400 TR capacity in life span of 20 years including spares

Charlieon09/27/2010

Cooling towers are used in all parts of the world.Each tower selection is designed for the specific geographic area,and yes they can be used in hot,humid climates.There needs to be a good source of water to replace that which is evaporated,which can sometimes be accomplished by catching the condensation.Hope this helps.

Amiron09/24/2010

What about geographical area? or is cooling tower as efficient in worm climets with high humidty?